Editing Piccadilly line (section)

==Architecture==
{{multiple image
| align        = center
| direction    = horizontal
| header       = A variety of architecture on '''Piccadilly line''' stations
| header_align = center
| image1       = Russell Square station.jpg
| width1       = {{#expr: (150 * 1600/ 1200) round 0}}
| alt1         = Ox-blood [[terracotta]] with semicircular windows on first floor
| caption1     = [[Russell Square tube station|Russell Square]], by [[Leslie Green]]
| image2       = Sudbury Town stn main entrance.JPG
| width2       = {{#expr: (150 * 1600/ 1200) round 0}}
| alt2         = A red brick rectangular box shaped building with a [[concrete]] roof and two pairs of [[Glazing (window)|glazed]] screens
| caption2     = [[Sudbury Town tube station|Sudbury Town]], the exemplar station
| image3       = Southgate station building.JPG
| width3       = {{#expr: (150 * 1600/ 1200) round 0}}
| alt3         = A low circular building with a wide awning is surmounted by a glazed column with a metal ball on the top
| caption3     = [[Southgate tube station|Southgate]]'s unique roof by [[Charles Holden|Holden]]
| image4       = Arnos tube interior.jpg
| width4       = {{#expr: (150 * 1600/ 1200) round 0}}
| alt4         = Passimeter in a station ticket hall
| caption4     = [[Arnos Grove tube station|Arnos Grove]] with passimeter
}}
Most of the deep level stations opened in the first phase between Finsbury Park and Hammersmith were built to a design by [[Leslie Green]].{{sfn|Wolmar|2005|p=175}} This consisted of two-storey [[Steel frame|steel-framed]] buildings faced with dark oxblood red [[Glaze (metallurgy)|glazed]] [[terracotta]] blocks, with wide semi-circular windows on the upper floor. Earl's Court and Barons Court stations was built with a red brick building by Harry Wharton Ford,{{sfn|Wallinger|Self|Warner|Wolmar|2014|pp=155,277}} with semicircular windows on the second level and embedded names of the railways which operated through the station. Both station buildings are Grade II listed,<ref name="eh_1358162">{{NHLE|num=1358162|desc=Earl's Court Station |access-date=18 August 2020}}</ref><ref name="EH 1358562">{{National Heritage List for England| num=1358562| desc=Barons Court Underground Station |access-date=1 November 2020}}</ref> and this building design at the former replaced a wooden hut building.{{sfn|Day|Reed|2010|p=24}}{{sfn|Martin|2012|p=79}}

Extensions of the Piccadilly line towards the west and north in the 1930s had new stations designed by [[Charles Holden]] of Adams, Holden & Pearson architectural practice. These designs were inspired by modern architecture seen in a 1930 trip to several European Countries.{{sfn|Horne|2007|p=61}}<ref>{{cite web |title=Underground Journeys: Changing the face of London Underground |url=http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/VARIBAArchitecturePartnershipexhibitions/UndergroundJourneys/ChangingthefaceofLondonUnderground/ChangingTheFaceOfLondonUnderground.aspx |publisher=[[Royal Institute of British Architects]] |access-date=19 February 2011 |url-status = dead|archive-url=https://web.archive.org/web/20110504024645/http://www.architecture.com/LibraryDrawingsAndPhotographs/Exhibitionsandloans/VARIBAArchitecturePartnershipexhibitions/UndergroundJourneys/ChangingthefaceofLondonUnderground/ChangingTheFaceOfLondonUnderground.aspx |archive-date=4 May 2011 }}</ref>

Several stations on the western extension originally built by the District Railway were reconstructed. The new designs used brick, concrete and glass to construct simple geometrical shapes, such as cylinders and rectangles. The first prototype station was [[Sudbury Town tube station|Sudbury Town station]], which has a brick cuboid box topped with a concrete slab roof for the main structure, with tall windows above the entrances. This design was replicated across many other stations.{{sfn|Cherry|Pevsner|1991|p=140}} Due to the workload, some stations' designs were carried out as collaborations with the Underground's own Architect, [[Stanley Heaps]] (Boston Manor, Osterley, Ealing Common and Hounslow West), or architects from other practices ([[Reginald Uren]] for Rayner's Lane) or entirely by another practice in Holden's style (Felix Lander for Park Royal).{{sfn|Powers|2007}}{{sfn|Day|Reed|2008|p=114}} The new stations built for the northern extension were also part of the design schemes undertaken by Holden. Southgate was distinctively different, with a round base carrying a cylindrical panel of [[clerestory]] windows, topped by an illuminated feature with a bronze ball.{{sfn|Day|Reed|2008|p=103}} The ticket halls had passimeters, which functioned as free-standing ticket booths. Most of them ceased to be used when automatic ticket gates were introduced, although some have been converted for retail use.{{sfn|Horne|2007|pp=82,131}} Many of these Holden-designed stations are [[listed building]]s, Oakwood, Southgate, and Arnos Grove being among the early receivers in 1971.{{sfn|Horne|2007|p=82}}<ref name="eh_1358981">{{NHLE|num=1358981 |desc=Arnos Grove Underground Station |access-date=18 August 2020 }}</ref><ref name="eh_1188692">{{NHLE | num=1188692 | desc=Southgate Underground Station | access-date=18 August 2020 }}</ref><ref name="eh_1078930">{{NHLE |num=1078930 |desc=Oakwood Underground Station |access-date=18 August 2020}}</ref>

Stations in Central London were modernised. Green Park received a new shelter at the southern entrance; Piccadilly Circus had its ticket hall moved below street level. Both of these changes were designed by Holden,{{sfn|Karol|2007|pp=481–484}} with the latter's station ticket hall having artwork commemorating Frank Pick added in 2016.<ref>{{Cite web|title=Train of thought: artists Langlands & Bell celebrate Frank Pick's design philosophy|url=https://www.wallpaper.com/art/langlands-bell-celebrate-frank-pick-design-philosophy-at-piccadilly-circus|last=Magazine|first=Wallpaper*|date=7 November 2016 |website=Wallpaper*|access-date=18 August 2020 |url-status=live |archive-url=https://web.archive.org/web/20200818170637/https://www.wallpaper.com/art/langlands-bell-celebrate-frank-pick-design-philosophy-at-piccadilly-circus |archive-date=18 August 2020}}</ref><ref>{{Cite web|title=Beauty < Immortality|url=https://art.tfl.gov.uk/projects/beauty-immortality/|website=Art on the Underground|language=en |access-date=18 August 2020 |url-status=live |archive-url=https://web.archive.org/web/20200818170339/https://art.tfl.gov.uk/projects/beauty-immortality/ |archive-date=18 August 2020}}</ref> Green Park also was built with a new entrance at a corner of Devonshire House, which has Portland Stone clad steel frames.{{sfn|Connor|2006|p=106}} It features [[Greco-Roman world|Graeco-Roman]] details, and is Grade II listed.<ref name="eh_1226746">{{English Heritage List entry |num=1226746 |desc=Devonshire House |access-date=18 August 2020}}</ref> Some stations kept their original buildings. [[South Ealing tube station|South Ealing]], where a temporary wooden station ticket hall was constructed when the line was quadrupled, was an anomaly; a modern station was not provided until the 1980s.{{sfn|Horne|2007|p=55}}{{sfn|Wallinger|Self|Warner|Wolmar|2014|p=287}}{{refn|Sources differ by year. Horne's mentioned 1989, while Wallingers' mentioned 1983.|group=note}}

Green's stations such as [[Caledonian Road tube station|Caledonian Road]] have bands of tiles arching overhead on the curved platform ceilings and above the tracks spaced {{convert|11–12|ft|m|abbr=on}} apart. Along the platform walls, geometrical patterns of tiles were arranged in a horizontal band; varying among stations. Arc lighting was complemented with incandescent lamps to illuminate the platforms. Signage decorations, also designed by Green, present spelt out the station name in letters {{convert|15|in|cm|abbr=on}} high.{{sfn|Horne|2007|p=22}}<ref name="eh_1401086">{{National Heritage List for England |num=1401086 |desc=Caledonian Road Underground Station |access-date=18 August 2020}}</ref>{{sfn|Wolmar|2005|p=175}}{{refn|This decoration concept was tested and worked on Bakerloo line stations, showing uniform style yet giving each station a unique appearance.{{sfn|Horne|2007|p=22}}|group=note}} Stations on the northern extension had particular biscuit (square) tiles on platform walls, with different [[frieze]] colours at each station. A few stations like Southgate and Bounds Green have [[art deco]] uplighters on escalators and the lower landings.<ref name="eh_1188692"/><ref name="eh_1393641">{{National Heritage List for England |num=1393641 |desc=Bounds Green Underground Station (Including No. 38) |access-date=3 April 2015}}</ref> [[Floodlighting]] was used considerably to provide a spacious ambience. [[Ventilation duct]]s were by the platforms walls, sealed with bronze art deco style [[Grille (architecture)|grille]]s.{{sfn|Horne|2007|pp=86–87}} Oakwood was built with a concrete canopy, with roof lights and cylindrical light fittings designed by Heaps.<ref name="eh_1078930"/>